Morphology of the compound eyes as an indicator of life-style in carabid beetles

Abstract

Twelve diurnal, 9 nocturnal, and 6 intermediate species of carabid beetles common in central Europe were investigated with respect to hunting behaviour and the morphology of the head and eyes. Diurnal visual hunters are characterized by typical visually guided predatory behaviour, which consists of a turn toward the prey, followed by a jerky approach and a lunge. Nocturnal species do not react to visual stimuli but use exclusively chemical or tactile cues for orientation. Visual hunters have broader heads than the other two groups (≈ 26% of the body length as opposed to ≈ 20%), shorter antennae (≈ 45% of the body length compared with ≈ 52% in the other two groups), ≈ 50% larger eye surfaces, and, correspondingly, 50% more ommatidia per eye. The binocular overlap of the frontal visual fields of both eyes is more than 50° in visual hunters; in nocturnal and intermediate species it is usually less than 40°. Nearly all species have acute zones with small interommatidial angles in the frontolateral parts of the eye, but in visual hunters these are much more distinct. As a readily measurable indicator of the hunting behaviour and life-style of a species we describe an eye–antenna angle that is more than 60° in typical visual hunters and, in most cases, much less than 55° in nocturnal species.

Variation of eye size in butterflies: inter‐ and intraspecific patterns

“…This prediction has been well supported (Horridge, 1977;Wehner, 1981;Land, 1989Land, , 1990Land, , 1997Warrant & McIntyre, 1992. As a relevant example of interspeci®c differences, a comparative study of 27 species of predaceous carabid beetles (not controlled for phylogeny) revealed that diurnal and visually hunting species have consistently larger eyes with more ommatidia, greater binocular overlap and more wellde®ned frontolateral acute zones than species that hunt nocturnally using non-visual cues (Bauer & Kredler, 1993).…”

Eye morphology reflects habitat demands in three closely related ground beetle species (Coleoptera: Carabidae)

“…They turn towards moving prey objects, approach in short jerks and attack with a fast lunge from close distance (for details of this behaviour see Bauer & Kredler, 1993). Normally, eye features like surface area and number of ommatidia are enlarged isometrically with increasing body size in Carabidae, while the interommatidial angles of the acute zones decrease (Bauer & Kredler, 1993). This may be partly because the relevant biological dimensions grow with increasing body size.…”

Role of Vision and Antennal Olfaction in Habitat and Prey Location by Three Predatory Heteropterans

“…Predatory insects may respond to chemical, visual, contact, and vibratory stimuli while searching for herbivorous prey (Hassell and Southwood 1978, Gogala 1985, Raveret Richter and Jeanne 1985, Hagen 1986, Zrzavy 1990, Hendrichs et al 1994, McIntyre and Vaughn 1997, Harmon et al 1998); may search randomly until they become relatively close to or actually make physical contact with a prey item (Hodek 1973, Hattingh andSamways 1995); or may employ different strategies depending on prey density, abiotic conditions, hunger, or other factors (Wallin andEkbom 1994, OÕNeil 1997). Interestingly, many invertebrate predators, particularly adults with welldeveloped eyes, do not rely on vision to locate prey, but instead use olfactory or vibratory signals (Raveret Richter and Jeanne 1985, Hagen 1986, Bauer and Kredler 1993, Rani and Wakamura 1993, Hendrichs et al 1994, Pfannenstiel et al 1995.…”