Jalysus wickhami

Van Duzee, 1906

Spined Stilt Bug

Jalysus wickhami, commonly known as the spined , is a of stilt bug in the . It is the most common stilt bug in the eastern United States and has been documented from gardens and meadows. The species exhibits feeding habits, consuming juices from legumes, grasses, and tomato plants, as well as preying on and . It has been studied for its role in and its potential negative impacts through intraguild on parasitoids.

Jalysus wickhami by no rights reserved, uploaded by Ken Kneidel. Used under a CC0 license.

Jalysus wickhami P1090519a by
xpda. Used under a CC BY-SA 4.0 license.

Jalysus wickhami P1090518a by
xpda. Used under a CC BY-SA 4.0 license.

Pronunciation

How to pronounce Jalysus wickhami: /ˈd͡ʒælɪsəs ˈwɪk.hæmi/

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

Distinguished from the closely related Jalysus spinosus by specific morphological characters detailed in taxonomic . possess fully developed , while have . The combination of spined body, stilt-like legs, and overall body proportions separates it from other . Keys to adults and fifth are available in taxonomic literature.

Images

Appearance

are slender, elongate with extremely long, stilt-like legs characteristic of the . The body is typically pale to with darker markings. A diagnostic feature is the presence of on the body, which distinguishes it from similar . The are long and thread-like, and the () is slender and curved beneath the . Fifth can be distinguished from adults by their and overall body proportions.

Habitat

Gardens, meadows, and agricultural fields. Associated with sticky plants such as tarweed (Madia elegans) where it navigates resinous or hooked to on trapped or other . Also found on plants including legumes, grasses, and solanaceous .

Distribution

North America and Central America. In the United States, recorded from every continental state except Alaska, New Hampshire, and Vermont. In Canada, present in British Columbia, Manitoba, Ontario, and Quebec. In Mexico, documented from Baja California Sur, Chihuahua, Coahuila, Durango, Hidalgo, Nuevo León, Tamaulipas, and Zacatecas.

Seasonality

Active from summer through autumn. peak in late summer and early fall, with likely occurring as .

Diet

. Feeds on juices from legumes, grasses, and tomato plants. Preys on of the (Manduca sexta), and of the Cotesia congregata, and (Myzus nicotianae). Requires a tobacco leaf substrate for long-term survival; animal is necessary for egg production.

Host Associations

Nicotiana tabacum - substrate leaf necessary for long-term survival; provides moisture or nutrients not obtained from alone
Manduca sexta - consumed as food source; highly acceptable that supports high
Cotesia congregata - intraguild and consumed; represents intraguild that may disrupt
Myzus nicotianae - consumed, though supports lower than lepidopteran or
Madia elegans - Tarweed; sticky that traps tourists, providing carrion that attracts including J. wickhami
Solanum lycopersicum - food sourceTomato ; feeding on plant juices can cause unripe fruit to drop
Fabaceae - food sourceLegumes; juices consumed
Poaceae - food sourceGrasses; juices consumed

Life Cycle

Develops through and five nymphal to . Overwinters as adult. In laboratory conditions, females feeding on high-quality (Manduca sexta eggs or Cotesia congregata ) produce approximately 100-106 per female, while those feeding on produce approximately 24 nymphs per female.

Behavior

Navigates sticky surfaces to access . Engages in intraguild , consuming other within the same trophic . Younger are more vulnerable to predation than older pupal stages. Attachment of parasitoid prepupae to tissue provides partial protection against predation.

Ecological Role

and in agricultural and natural . Functions as a agent by preying on pest such as those of Manduca sexta. However, intraguild on such as Cotesia congregata may negatively impact biological control programs. Presence on sticky plants contributes to a defensive where trapped carrion attracts predators that reduce damage.

Human Relevance

Considered a in some agricultural contexts due to on pest . However, feeding on tomato juices can cause by inducing premature fruit drop. Intraguild predation on may reduce effectiveness of strategies. Has been studied as a model organism for understanding omnivory and intraguild predation in systems.

Similar Taxa

Jalysus spinosusClosely related congeneric ; distinguished by morphological characters detailed in taxonomic
Hoplinus echinatusCo-occurring found on same sticky plants; both navigate tarweed

More Details

Intraguild Predation Dynamics

Jalysus wickhami represents a case where a 'good ' can have negative impacts on . Its on Cotesia congregata and —another of the same pest (Manduca sexta)—can disrupt pest suppression. Younger stages suffer higher mortality (61-67% for prepupae and 0-1 day-old pupae) than older pupal stages (14-38% for 2-3 day-old pupae). Because C. congregata overwinters as prepupae, it may be particularly vulnerable to attack late in the season when are large and are relatively uncommon.

Nutritional Requirements

Laboratory studies demonstrate that J. wickhami has specific nutritional requirements: a substrate ( leaf) is essential for long-term survival (>21 days versus <12 days without), while animal is required for production. This dual requirement reflects its nature and distinguishes it from strictly predatory or strictly .