Flight polymorphism in the field cricket Gryllus pennsylvanicus.

Area of Science:

• Evolutionary biology
• Genetics
• Animal behavior

Background:

• Wing length polymorphisms are prevalent in insects.
• The field cricket Gryllus pennsylvanicus exhibits variable frequencies of the long-winged morph across populations.
• Understanding the genetic basis of such polymorphisms is crucial for evolutionary studies.

Purpose of the Study:

• To investigate the genetic underpinnings of wing length variation in Gryllus pennsylvanicus.
• To determine if genetic differences explain the observed inter- and intrapopulation variation in flight morph frequencies.
• To explore potential mechanisms maintaining this flight polymorphism.

Main Methods:

• Laboratory rearing experiments were conducted.
• Single-pair crosses were performed to analyze inheritance patterns.
• A genetic variation in threshold response model was developed and tested against empirical data.

Main Results:

• Laboratory experiments and genetic crosses indicated that genetic differences contribute significantly to wing length variation.
• Inter- and intrapopulation differences in morph frequencies are at least partly explained by genetic factors.
• A threshold response model effectively accounts for the observed data.

Conclusions:

• Genetic variation plays a key role in the wing length polymorphism of Gryllus pennsylvanicus.
• The observed distribution of flight morphs can be explained by genetic differences influencing a threshold response.
• Further research is needed to elucidate the specific mechanisms maintaining this polymorphism in natural populations.