CN113678790B - A method to optimize the population structure of Leucopteris bancroft by means of host switching - Google Patents

Abstract

The invention relates to the technical field of indoor breeding of insects, in particular to a method for optimizing a small-sized bombus swarm structure in a host conversion mode. The host switching cycle specifically comprises the following steps: s1, selecting a bombus batrachius PSS-1 which takes the Chinese hibiscus mealybugs as hosts to breed a plurality of generations; s2, providing the transformed host lycoris radiata mealybugs for the bombus sp PSS-1, and obtaining the bombus sp PSI-1 after the first host transformation after the progeny parasitic wasps eclosion; and S3, providing the Hippocampus solonensis PSS-1 for parasitism of the Brachypoda rupestris after host conversion to obtain the Brachypoda rupestris PSS-2 after the second host conversion. Namely 2 times of the Liriospirus fuscipes parasitized by the Beauveria bambusicola (generating PSS-1 and PSS-2) and 1 time of the Lycoris radiata (generating PSI-1), in order to complete one host conversion cycle. And continuing host switching for the second period (generating PSS-3, PSI-2 and PSS-4) and the third period (generating PSS-5, PSI-3 and PSS-6), so that the population optimization of the Brachidaceae jumping wasps can be realized. The method can obviously improve the parasitic rate of the female bee of the Brazilian jumping bee, prolong the service life of the female bee and the male bee, increase the proportion of offspring female bees in the population and greatly optimize the population structure of the Brazilian jumping bee.

Description

A method to optimize the population structure of Leucopteris bancroft by means of host switching

technical field

The invention relates to the technical field of indoor breeding of insects, in particular to a method for optimizing the population structure of Leaperia bancroft by means of host conversion.

Background technique

Both Phenacoccus soleopsis and Phenacoccus solani belong to the genus Phenacoccus, and their host spectrums are generally similar. Aenasius bambawalei belongs to the family Hymenoptera, and it is an important companion natural enemy of Fuso cotton mealybug and an obligate parasitoid of its dominant species. Its parasitic rate in the wild is as high as 50% to 62%. Good prospects for biological control applications. At present, a lot of research has been carried out at home and abroad on the use of Aenasiusbambawalei to biologically control Pythococcus hibiscus, but there is no report on the parasitic natural enemies of Pythococcus amaryllis. At the same time, there are few reports on the expansion and utilization of new host resources and the host adaptation mechanism of Le. bancroftensis to other new host resources except P. fusoi. Through indoor breeding, we found that after a short period of adaptation, the wasp can successfully parasitize the mealybug Amaryllidin. However, the effects of host switching on Le. bancrofti on its parasitic characteristics and population structure are not yet clear.

Contents of the invention

In order to solve the above-mentioned technical problems, the present invention provides a method for optimizing the population structure of A. bancrofti by means of host switching, which can significantly improve the parasitism rate of females of A. bancrofti, prolong the life span of male and female bees, and increase the number of offspring in the population. The proportion of female bees greatly optimizes the population structure of Leaperia bancrofti, which helps to fully develop and utilize Leaperia bancrofti, and also provides new ideas for the prevention and control of invasive pests that lack companion natural enemies in newly invaded areas .

Technical scheme of the present invention is as follows:

A method for optimizing the population structure of E. bancrofti by means of host switching. The host switching cycle specifically includes the following steps: S1, select the PSS of Pythias bancrofti for multiple generations of feeding with Fuso cottonian mealybug as a host; S2, for the above PSS provides the converted host Amaryllis chinensis, and after the emergence of its offspring parasitoid wasps, PSI of the first host conversion is obtained; The bee PSI provided the Pythococcus hibiscus for parasitism, and the second host conversion was obtained after the second host conversion of the Leapertia bancroft PSS-2. That is to say, A. bancroft parasitizes Pythococcus hibiscus twice (producing PSS-1 and PSS-2) and P. amaryllis (producing PSI-1) once, to complete a host switching cycle. Continue the second cycle of host conversion (produce PSS-3, PSI-2 and PSS-4) and the third cycle (produce PSS-5, PSI-3 and PSS-6), and then the population optimization of Bancroft's jumping bee can be realized . Preferably, the multi-generation PSS of Leucoccus bancrofti is raised indoors for at least 30 generations.

Preferably, the indoor breeding conditions are set at 26-28° C., relative humidity of 70-80%, and photoperiod of L16:D8.

Preferably, the transformed host is a female adult, and the bee:scale ratio is 2:15.

Preferably, the mealybug Pyococcus hibiscus provided for the PSI of L. bancrofti after host conversion is a female adult, and the ratio of wasp:scale is 2:20.

Compared with the prior art, the present invention has the following advantages:

The present invention adopts the Pythococcal hibiscus as the host and raises the Leucopteris bancroft for more than 30 generations as the initial source of parasitoids. It can ensure the high parasitization rate of the converted host, the individual size of the bee and the life span of the offspring female bee.

The present invention adopts the mealybug Lycoris spp. as the conversion host of the bee bancroft, which not only helps to increase the parasitization rate of the mealybug, but also helps to expand the host spectrum of accompanying natural enemies, and to control alien invasive species lacking natural enemy resources.

The invention re-provides the hibiscus cottonian mealybug host for the Leaperia bancrofti after host conversion, helps to increase the parasitism rate of the female bee of the Leaperia bancrofti, prolongs the lifespan of the male and female bees, and increases the proportion of female bees of offspring in the population.

Description of drawings

Figure 1 is a schematic diagram of the implementation.

Detailed ways

The present invention provides a method for optimizing the population structure of T. bancrofti by means of host switching. The host switching cycle specifically includes the following steps: S1. Selecting Pycnophagia bancrofti PSS for multiple generations as a host; S2, providing the converted host Amaryllis lyricoccus for the above-mentioned PSS of Leaperia bancrofti, after the emergence of its offspring parasitoids, obtain the PSI of Leaperia bancrofti after the first host conversion; S3, for the PSI after the host conversion PSI provides P. hibiscus for parasitism, and obtains PSS-2 after the second host conversion. That is to say, A. bancroft parasitizes Pythococcus hibiscus twice (producing PSS-1 and PSS-2) and P. amaryllis (producing PSI-1) once, to complete a host switching cycle. Continue the second cycle of host conversion (produce PSS-3, PSI-2 and PSS-4) and the third cycle (produce PSS-5, PSI-3 and PSS-6), and then the population optimization of Bancroft's jumping bee can be realized .

Example 1 Effects of different host switching modes on the fitness of Leaperia bancroft

Under laboratory conditions, Potato Solanum tuberosum potted seedlings (20-25cm) and potato tubers were used to raise Pythysporum hibiscus and Pycoccus amaryllis respectively. After the two kinds of mealybugs develop into female adults, they are ready for use. Two pairs of newly emerged and fully mated Pythias bancrofti (two females and two males) were selected indoors and raised at least 30 generations with Pyenococcus hibiscus as the host. The parasitoid wasps were removed after feeding for 48 hours with T2 host sequence (P. Among them, the bee:scale ratios of A. bancrofti, P. hibiscus and P. amaryllis were 2:20 and 2:15, respectively. After the above parasitic wasps eclosion, the T1 and T2 host sequences obtained by the T1 and T2 hosts, respectively, were inserted into T. bancroft and P. fuso at a ratio of 1:30. The parasitization rate, eclosion rate, female ratio of progeny and lifespan of male and female bees were counted. Each of the above treatments was repeated 5 times, and P. bancrofti, which was eclosion with P. hibiscus cottonii as the host, was used as the control. The indoor breeding conditions were set at 26-28°C, relative humidity at 70-80%, and photoperiod L16:D8.

Table 1 Effects of different host switching methods on the fitness of Leucopteris bancrofti

T1 T2 CK Parasitic rate (%) 64.67±2.35A 30.00±1.26C 56.67±2.25B Feather rate (%) 92.88±3.44A 88.83±2.35A 91.85±3.20A Female bee lifespan (d) 29.60±2.36A 8.60±1.14C 27.8±1.24B Drone Lifespan (d) 13.80±0.15A 5.60±1.03C 7.00±1.56B Proportion of offspring females (%) 76.70±5.31A 54.68±3.24B 45.14±5.37C

Note: Capital letters indicate significant differences among different treatments.

It can be seen from Table 1 that the T1 host switching mode (Pythococcus hibiscus-Pycoccus amaryllis-Pycoccus lycoides) can significantly increase the parasitism rate of A. bancrofti and prolong the lifespan of the offspring of female bees and male peaks. And increase the proportion of female offspring; T2 host conversion mode (Lycoccus lycoides-Pycoccus hibiscus-Pycoccus lycoris) can not only increase the proportion of female offspring, but the parasitism rate, female bee and male peak lifespan are all lower than (shorter than) the control; under the two host switching modes, there was no difference in the eclosion rate of L. bancrofti compared with the control. It can be seen that the host switching mode of T1 (Pythococcus hibiscus - Pythococcus amaryllis - Pythococcus fuso) is more conducive to the optimization of the population of A. bancrofti.

Example 2 Effects of different host conversion cycles on the parasitism rate and the sex ratio of the population of Leviathan bancroft

Select T1 host order (Pythococcus lycoccus-Pycoccus lycocili-Pycoccus lycoides) for 1, 2, 3, 4 and 5 cycles of reproduction of the population of Leucopteris bancroft, with a bee:scale ratio of 1:30 The proportion of P. hibiscus was provided as a host for it. Observe and count the total number of Fuso mealybugs parasitized by E. bancroft's each generation and the proportion of female bees in the offspring every day. Each of the above treatments was repeated 3 times, and P. bancrofti, which was eclosion from Pycoccus hibiscus cotton as the host, was used as the control. The indoor breeding conditions were set at 26-28°C, relative humidity at 70-80%, and photoperiod L16:D8.

Table 2 Effects of different host conversion generations on the parasitism rate and the sex ratio of the population of A. bancrofti

Note: Capital letters indicate significant differences among different generations.

It can be seen from Table 2 that the parasitism rate and the proportion of female offspring of Leaperia bancroft can be significantly increased by switching between different cycles by T1 host switching. Among them, the parasitism rate and the proportion of offspring females gradually increased with the increase of the transition period, and reached the maximum at the third period, and then both values continued to decrease and approached the level at the first transition period.

The implementation diagram is shown in Figure 1.

Claims (3)

1. A method for optimizing a Babylonia wasp population structure in a host conversion mode is characterized by comprising the following steps: the host switching cycle specifically comprises the following steps: s1, selecting and breeding a plurality of generations of Beehive beetle PSS-1 by taking the Hippoicerus soloniella as a host, and selecting bees of the Beehive beetles and the Hippoicerus soloniella: the scale of the scale is 2:20; s2, providing the hosts of the above Beauveria bambusicola PSS-1 with the bees of the Beauveria bambusicola and the Lycoris radiata Leonia: the scale of scale is 2:15; after the offspring parasitic wasps emerge, obtaining PSI-1 of the Bangian jumping wasp after the first host conversion; s3, providing the cotton bollworm for the small bane-Shi PSI-1 after host conversion for parasitizing to obtain the small bane-Shi PSS-2 after the second host conversion, namely parasitizing the small bane-Shi for 2 times to generate PSS-1 and PSS-2 and 1 time to generate PSI-1 by the cotton bollworm of lycoris, and completing a host conversion period; continuing host switching for a second period to generate PSS-3, PSI-2 and PSS-4 and PSS-5, PSI-3 and PSS-6 in a third period, so as to realize the population optimization of the Brachypodium banseyi, wherein the raising of the Brachypodium shikoyi PSS-1 for a plurality of generations by taking the Lecanicillium solenopsis as the host means that the Brachypodium banseyi is raised indoors for at least 30 generations; indoor breeding conditions are set to be 26-28 ℃, relative humidity is 70-80%, and photoperiod is L16: D8.

2. The method for optimizing the structure of a population of Brachypodium bambusicola by host transformation according to claim 1, wherein the insect status of the transformed hosts is female adults.

3. The method for optimizing the population structure of the Potentilla anserina through the host transformation method according to claim 1, wherein the Coccinia fusca PSI-1 provides the Potentilla anserina in the form of female adults, and the bee: the scale of the scale is 1:30.

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