Alphomelon

General description: 

General comments:

Although the conspicuous white coloration of the genae helps to define Alphomelon, it should not be the only character used for identification. Species of Apanteles, Cotesia, Dolichogenidea, Prasmodon, and a new (undescribed) genus from New Zealand also have white patches on the genae (Mason 1981, Deans et al. 2003, Fernandez-Triana et al. 2014, Ward & Fernandez-Triana, unpublished data). Additional characters that distinguish Alphomelon from other genera with white genae include: fully sclerotized hypopygium, presence of petiolar ridge, lack of wing areolet, and fully carinate propodeum with areola.

Color patterns are the most obvious and perhaps easiest characters to use for diagnosis of certain species, for example: conspicuous body segment coloration of orange or yellow, or size of white spots on the genae, Additional characters include coloration of legs (completely orange or barred with black), wings (smoky or hyaline), ovipositor (reddish-orange or yellow), and face (with a light brown spot or completely black). Although these color patterns appear to be largely diagnostic, caution should be used when relying on color characters alone since temperature during development is known to influence adult appearance in braconids (Liu and Carver 1982).

Other diagnostic morphological characters concern hind wing vein cu-a curvature, tarsal claw spine number, ovipositor length and curvature, lunule shape, tegula shape and color, propodeal sculpturing (areola open or closed anteriorly), metasomal tergite I and II shape, and sculpturing of the head and mesoscutum (Deans et al. 2003).

The following detailed description of the genus is from Deans et al. (2003):

Diagnosis. Genae with white coloration. Face with prominent ridge medially. Forewing without areolet. Propodeum areolated. Tarsal claws pectinate. Hypopygium evenly sclerotized.

Description. Head: Brown to black with white coloration on genae. Head broad in frontal view, usually punctate, setose with spreading hairs, always with nitid frons, occiput and vertex. Prominent ridge arising between antennaI sockets and continuing ventrally to point 0.5 between antennal shelf and clypeus. Antennae: Light brown to black, as long as body. Placodes in two rows. Mouthparts: Mandible with two teeth: one pointed (dorsal), one rounded (ventral). Eyes and Ocelli: Eyes silver (red or dull gray in older specimens) stiffly setose with short hairs. Ocelli clear to translucent red, subequal in size with median ocellus immeasurably (85%) smaller. Mesosoma: Propleuron anteriorly punctate and setose with hairs arising from depressions, posteriorly nitid. Pronotal polished band nitid anteriorly and substrigulate posteriorly. Pronotal furrows rugose. Area posterior to pronotal furrows punctate and setose. Epirneron deeply impressed dorsally. Mesoscutum punctate (85%) broader than long. Anterior scutellar furrow represented by line of impressed pits. Lateral scutellar furrows widening apically. Lunules nitid. Axillary projections costate-rugose. Lateral metanotal area areolate-rugose dorsally and nitid ventrally. Propodeum sculptured and areolated. Legs: Variably patterned with black, brown, yellow, and white, covered with short, stiff setae. Tibiae with short spines randomly distributed throughout surface. Tarsal claws pectinate with 1-4 spines. Wings: Setose with hairs more dense apically. Forewing without areolet. Hamuli consisting of 3 spines basally and 3 hooks distally. Metasoma: Petiole with short bifurcating carina present medially (if no carina then shallow depression present). Medial tergite II trapezoidal to rectangular, nitid to rugulose. Tergite I spiracle surrounded with long thickened setae. Hypopygium evenly sclerotized. Genitalia: Ovipositor tapering apically, slightly depressed dorsally basal to tip and slightly expanded at tip. Ventral valve with 24 teeth apically. Ovipositor sheaths evenly setose with stiff spreading setae at the desclerotized tips.

General comments:

Although the conspicuous white coloration of the genae helps to define Alphomelon, it should not be the only character used for identification. Species of Apanteles, Cotesia, Dolichogenidea, Prasmodon, and a new (undescribed) genus from New Zealand also have white patches on the genae (Mason 1981, Deans et al. 2003, Fernandez-Triana et al. 2014, Ward & Fernandez-Triana, unpublished data). Additional characters that distinguish Alphomelon from other genera with white genae include: fully sclerotized hypopygium, presence of petiolar ridge, lack of wing areolet, and fully carinate propodeum with areola.

Color patterns are the most obvious and perhaps easiest characters to use for diagnosis of certain species, for example: conspicuous body segment coloration of orange or yellow, or size of white spots on the genae, Additional characters include coloration of legs (completely orange or barred with black), wings (smoky or hyaline), ovipositor (reddish-orange or yellow), and face (with a light brown spot or completely black). Although these color patterns appear to be largely diagnostic, caution should be used when relying on color characters alone since temperature during development is known to influence adult appearance in braconids (Liu and Carver 1982).

Other diagnostic morphological characters concern hind wing vein cu-a curvature, tarsal claw spine number, ovipositor length and curvature, lunule shape, tegula shape and color, propodeal sculpturing (areola open or closed anteriorly), metasomal tergite I and II shape, and sculpturing of the head and mesoscutum (Deans et al. 2003).

The following detailed description of the genus is from Deans et al. (2003):

Diagnosis. Genae with white coloration. Face with prominent ridge medially. Forewing without areolet. Propodeum areolated. Tarsal claws pectinate. Hypopygium evenly sclerotized.

Description. Head: Brown to black with white coloration on genae. Head broad in frontal view, usually punctate, setose with spreading hairs, always with nitid frons, occiput and vertex. Prominent ridge arising between antennaI sockets and continuing ventrally to point 0.5 between antennal shelf and clypeus. Antennae: Light brown to black, as long as body. Placodes in two rows. Mouthparts: Mandible with two teeth: one pointed (dorsal), one rounded (ventral). Eyes and Ocelli: Eyes silver (red or dull gray in older specimens) stiffly setose with short hairs. Ocelli clear to translucent red, subequal in size with median ocellus immeasurably (85%) smaller. Mesosoma: Propleuron anteriorly punctate and setose with hairs arising from depressions, posteriorly nitid. Pronotal polished band nitid anteriorly and substrigulate posteriorly. Pronotal furrows rugose. Area posterior to pronotal furrows punctate and setose. Epirneron deeply impressed dorsally. Mesoscutum punctate (85%) broader than long. Anterior scutellar furrow represented by line of impressed pits. Lateral scutellar furrows widening apically. Lunules nitid. Axillary projections costate-rugose. Lateral metanotal area areolate-rugose dorsally and nitid ventrally. Propodeum sculptured and areolated. Legs: Variably patterned with black, brown, yellow, and white, covered with short, stiff setae. Tibiae with short spines randomly distributed throughout surface. Tarsal claws pectinate with 1-4 spines. Wings: Setose with hairs more dense apically. Forewing without areolet. Hamuli consisting of 3 spines basally and 3 hooks distally. Metasoma: Petiole with short bifurcating carina present medially (if no carina then shallow depression present). Medial tergite II trapezoidal to rectangular, nitid to rugulose. Tergite I spiracle surrounded with long thickened setae. Hypopygium evenly sclerotized. Genitalia: Ovipositor tapering apically, slightly depressed dorsally basal to tip and slightly expanded at tip. Ventral valve with 24 teeth apically. Ovipositor sheaths evenly setose with stiff spreading setae at the desclerotized tips.

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith