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United States Department of Agriculture

Agricultural Research Service

Research Project: MASS PRODUCTION OF BIOLOGICAL CONTROL AGENTS

Location: Biological Control of Pests Research Unit

Title: Mother-offspring relations: Maternal size and prey quality affect egg size of an acariphagous lady beetle in culture

Authors
item Riddick, Eric
item Wu, Zhixin

Submitted to: Psyche
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 10, 2012
Publication Date: June 14, 2012
Citation: Riddick, E.W., Wu, Z. 2012. Mother-offspring relations: prey quality and maternal size affect egg size of an acariphagous lady beetle in culture. Psyche. volume 2012, article ID 764350, 7p.

Interpretive Summary: The lady beetle Stethorus punctillum is one of the most important predators commercially available for control of crop-infesting mites, such as the two-spotted spider mite. We found that lady beetle mothers alter the size of their offspring (eggs) in response to the quality of food (spider mites) that they consume since birth. High quality food maximizes the growth of mothers. High quality food maximizes the size of eggs laid by mothers. This study describes the complex interactions between diet and growth of a lady beetle that feeds on spider mites.

Technical Abstract: We investigated maternal size – egg size relations in a specialized mite predator, Stethorus punctillum Weise (Coleoptera: Coleoptera). We tested these hypotheses: (1) prey quality affects egg size, (2) maternal size correlates with egg size, and (3) egg size affects hatching success. We reared predators on the two-spotted spider mite fed lima bean foliage under controlled conditions. Mothers consuming high rather than low quality prey since birth produce larger eggs. Egg size correlates positively with maternal size; egg size increases as femur length increases. Egg size does not affect hatch rate or hatch time. In conclusion, the quality of prey consumed by S. punctillum mothers while in the larval stage can affect their size as adults and, consequently, the size of their eggs. Other factors not identified in this study such as feeding rate and egg maturation (oogenesis) might contribute to the S. punctillum mother – progeny size relationship.

Last Modified: 8/29/2014