Mate finding

Laboratory observations remain essential because they can delineate the timing of mate finding and mating in relation to other activities, and observations can provide important information about interactions between the sexes and the role of sex pheromones. The identification of sex pheromones also requires standard laboratory behavioral assays. We urge students of cockroach behavior and chemical ecology to develop more realistic behavioral assays that will facilitate the identification of sex pheromones as well as a better understanding of their role in cockroach mating systems. 

Schal, C. (1982). Intraspecific vertical stratification as a mate-finding mechanism in tropical cockroaches. Science 215 1405-1407. 

Seelinger, G. (1984). Sex-specific activity patterns in Periplaneta americana and their relation to mate-finding. Journal of Comparative Ethology 65 309-326. 

Tsai, C.-W. and Lee, H.-J. (1997). Volatile pheromone detection and calling behavior exhibition secondary mate-finding strategy of the German cockroach, Blattella germanica (L.). Zoological Studies 36 325-332. 

This review considers evidence for selective forces that mold the chemical signal and behavioral response, including the characteristics of pheromone dispersal and the plume-tracking maneuvers that influence the success of mate finding. Recent reviews that consider mechanisms of evolutionary change in moth pheromones include Phelan (1992,1996,1997), Lofstedt (1993), Linn and Roelofs (1995), and Lofstedt and Kozlov (1996). 

De Jong, M.C.M. (1988). Evolutionary Approaches to Insect Communication Systems. Bark Beetle Host Colonization and Mate Finding in small ermine moths. Ph.D. Thesis, Leiden University. 

Landolt, P. J. and Heath, R. R. (1990). Sexual role reversal in mate-finding strategies of the cabbage looper moth. Science 249 1026-1028. 

What are some examples of these attractants (Figure 1) For mate finding, the insect-produced pheromones are the primary examples. However, environmental factors may also play an important role in the effectiveness of attractants. In the southern pine beetle, Dendroctonus frontalis. alpha-pinene released from an attacked tree is necessary along with the endogenously produced frontalin in order to attract males for mating (14). 

Figure 1. Attractants for mate finding, oviposition and food.

The most effective application technique for lepidopteran species is to permeate the atmosphere with synthetic pheromone, and to thereby prevent olfactory communication and mate finding. The mating disruption technique has been successfully applied in Europe to three lepidopteran insects from horticultural crops codling moth Cydia pomonella, and the grape berry moths Eupoecilia ambiguella and Lobesia botrana [132, 133]. 

Reproductive processes of helminths are diverse. The adults are hermaphroditic (monoecious) or dioecious, requiring, in some cases, no fertilization, in others, self- or cross-fertilization in hermaphrodites or insemination of females by males. Reproduction by monoecious species is simplified since no mate finding is necessary. In those species where separated sexes exist, and in hermaphroditic species where cross-fertilization is preferred, various adaptations have increased the likelihood of worm pairing and mate finding in the host. 

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