饥饿对扶桑绵粉蚧存活率和产卵量的影响

【背景】扶桑绵粉蚧是近年来入侵我国的重要害虫，食物是影响其生长发育及种群发展的重要因素。【方法】在室内条件下研究了饥饿对扶桑绵粉蚧不同龄期若虫和初羽化雌成虫存活率和雌成虫产卵量的影响。【结果】扶桑绵粉蚧不同虫态在饥饿条件下存活的时间存在显著差异，表现为雌成虫〉2龄若虫=3龄若虫〉1龄若虫。扶桑绵粉蚧各龄若虫和雌成虫随着饥饿时间的延长，存活率逐渐下降。其中，雌成虫存活率下降速度较慢，完全饥饿8d后存活率仍有50％左右；2、3龄若虫50％个体死亡需要饥饿的时间约为6d，1龄若虫约需5．5d。饥饿会显著降低1龄若虫存活率，但对2、3龄若虫没有显著影响。扶桑绵粉蚧雌成虫饥饿4d对其产卵前期、平均每头雌虫一生的产卵量没有显著影响，但寿命显著低于对照。【结论与意义】扶桑绵粉蚧耐饥力较强，这有助于它在野外建立种群。该结果为进一步评价扶桑绵粉蚧的入侵潜能提供了依据。

Effects of starvation on survival rate and oviposition of the invasive mealybug Phenacoccus solenopsis （ Hemiptera： Pseudococcidae）

Background]Phenacoccus solenopsis is an important pest that invaded to China in recently years. Food is an important factor affecting growth, development, and population development in insects, and access to food can be limited during invasions. Method] Survival rate and oviposition of different developmental stages of P. solenopsis were studied under laboratory conditions to determine their ability to survive extended periods of starvation. The effects of short periods （4 days） of starvation on longevity, preovitx/sition periods, oviposition of per female were also described. Result ] Survival rates of P. solenopsis in different stages and instars at starvation condition were different significantly： female adults were the most resistant, followed by 2nd instar nymph = 3rd instar nymph. 1 st instar P. solenopsis was the most vulnerable to starvation （starvation for 5.5 days, mortality rate ~50% ）. Female adults survived the longest during starvation （ starvation for 8 days, mortality rate 〈 50% ）. There were negative effects on 1 st instar nymphs and the survival rate decreased significantly. Starvation in the 2nd and 3rd instars larval had no significant effects on survival rates. There was not significant difference in oviposition when female adult experienced short periods （4 days） of starvation, whereas female longevity was shortened. Conclusion and significance] Starvation endurance ability of P. solenopsis was strong which could facilitate the survival and spread of this species, contributing to its invasiveness.