docArachnophobe to Arachnophile - Virginia Mosquito Control
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Arachnophobe to Arachnophile - Virginia Mosquito Control
Arachnophobe to Arachnophile Presented by: Wes Robertson Henrico County Standing Water Initiative Introducing the Spectacular Spider • Found worldwide • Found in a variety of climates • 42,000 plus species • 110 families • All are carnivores • All produce silk • All have fangs Comb-Clawed Spider – Theridiidae spp. What makes a spider a spider? 2 Body Segments Eyes Spinnerets Chelicerae 8 Segmented Legs Pedipalps Dysdera Crocata – Woodlouse Spider Why look beyond the eight legs? Velvet Ant Mimic Spider – Castianeira White-banded Daddy long amoena legs Crab–Spider Lebobunum – Misumenoides spp.Velvet (Not really formosipes Ant –a Dasymutilla spider) occidentalis The Developmental Cycle Spider shape is established Egg Cannot feed or mate Larva Nymph Adult Virginia Tan Jumping Spider Self-sufficient and sexually mature Continued Development Molting is the key to developmental progression. The average spider lives between 1-2 years and molts 3 and 15 times during that time. Therefore, immediately following the first molt, each spiderling must become adapted for hunting and capturing prey. However, they must first disperse. Spiders are a Key Component in Aerial Plankton The most common form of spider dispersal is ballooning. Spiders utilize rising air currents to move shortly after emergence. An Integral Pioneering Arthropod Wind Picks up Ballooning Occurs Established Territory Secondary Prey New acts Pioneering Succession asGrowth trapped Species nutrients Occurs Vacant Territory Why is this important? Young and old ecosystems depend on a fragile balance between competition and interdependence. While spiders are not effective biological control agents against specialized targets they help maintain balance within the insect world. This balance results in an increase in overall diversity. Developing the Ability to Identify, Then Recognize However, in order to understand their role in the ecosystem, we must develop an appreciation of their value and uniqueness. This is achieved through identification and recognition. Observe The key to basic identification is observation Observe the habitat and/or webs Dysdera crocata – Woodlouse spider Observe the prey options their movement, size, & body form Identify the Habitat and the Web Spring door with silk hinge Forest Floor Southern Trap-door Spider – Ummidia audouini Cellar Habitat Crevice with radial symmetry Southern House Spider –Crevice Weaver – Kukulcania spp. Identify the Habitat and the Web Garage and House Ceiling Garage Floor Tangle Webs Southern Black Widow Latrodectus mactans False Widow - Steatoda borealis House Spider – Parasteatoda tepidariorum No, not the same as this guy. (Opiliones a.k.a. Harvestman) Daddylonglegs (Cellar Spider) Pholcus phalangioides Identify the Habitat and the Web Mesh Web Dictyna arundina Hammock Spider Garden Plant Ceiling Corner Forest Understory Sac Web and Long-Legged Sac Spider Identify the Habitat and the Web Back porch and foundation bushes Front lawn or on sides of house Orchard Weaver Trash line Weaver Common Grass Spider Agelenopsis spp. Identify the Habitat and Web Tall Garden Vegetation Backyard Rock Hacklemesh Web Wagon Wheel Web Longjawed Orbweaver – Tertragnathidae spp. Hacklemesh Weaver Amaurobius ferox Identification of Webless Spiders • Ground Spiders • Jumping Spiders • Woodlouse Spiders • Recluse Spiders • Prowling Spiders • Wolf Spiders • Crab Spiders Identify the Size and Body Form Arrow-Shaped Micrathena Wall Spider Raptorial spine legs Crab Spider Forward Legs White-banded crab (Misumenoides formosipes) Magnolia Green Jumper Tiger Wolf Brown Recluse Size demonstration Identification of Different Sexes Males • Usually smaller • Thicker palpal tarsi • Final molt equals wandering • Stops eating during wandering • Can become female prey • Several mating events before dying Females • Larger • Live Longer • Lay eggs and build cocoons • Some exhibit brood care Visualization of Spider Sexes Dorsal Side Female Male Female Male Southern Black Widow – Latrodectus mactans Female –Ventral Side Yellow Garden Spider – Argiope aurantia Identifying Virginia’s Venomous Spiders • Latrodectus (Widow species) • Virginia has two widow species Southern Black Widow (Latrodectus mactans) II. Northern Black Widow (Latrodectus variolus) Mature Ventral View I. • Characteristic Hourglass patterns • Tangled Web (Extremely messy and low to the ground) • As big as a half dollar and clumsy when not in web Northern Southern Immature Dorsal View Differences Between Mature Females Northern - variolus Southern - mactans Differences Between Mature Females Northern - variolus Southern - mactans Differences Among Immature Females Northern - variolus Southern - mactans Identifying Venomous Spiders • Sicariidae • Brown Recluse • Not a Virginia Resident • Violin but better id through counting eye dyads Not Here! 3 dyads Recluse distribution Brown Recluse Identification • Fiddle present • Eye Dyads present • Generally quarter size • Generally nocturnal • Ground Spider – extremely fast Conclusion Arachnids have been around for 440 million years and there are roughly 38,000 species of spiders alone. This fact makes arachnids an amazingly diverse group of invertebrates. I have tried to introduce you to the basics of spider identification with the hope that, through practice, you too, will be able to recognize many common species with less malice and fear.
